Runs entirely in your browser - no upload, no sign-up.
Choose an image or load the example, then compare the original with a simulated view.
A color blindness simulator changes an image to approximate how colors may appear with protanopia, deuteranopia, tritanopia or achromatopsia. Upload a design or photo, choose a vision type and compare both views side by side. Processing stays in your browser, so the image is not uploaded.
Upload a PNG, JPG, WebP or AVIF file, drag it into the drop zone, or load the built-in color example.
Compare protanopia, deuteranopia, tritanopia or achromatopsia, then adjust the simulation strength if needed.
Inspect the original and simulated canvases side by side. Look for controls, labels or chart series that become hard to tell apart.
Copy the simulated image to the clipboard or download it as a PNG for review notes and issue reports.
Use the strength control to inspect a milder or full simulation, then copy or download the transformed image for a design review. Your image stays on your device; the browser reads its pixels, applies the selected transform and renders the result locally.
A simulation can reveal color pairs that collapse into similar tones, but it does not certify accessibility. Pair this check with contrast measurements, text labels, icons, patterns and user testing.
No. Your browser decodes the image, transforms its pixels and creates the preview locally. The tool does not send the file to a server. If the image is sensitive, you can use the simulator without creating an account or saving it online.
Yes. You can upload images, switch between the available simulation modes, change the strength and download results for free. There is no sign-up and no per-day usage limit.
The simulator accepts PNG, JPG, WebP and AVIF files up to 20 MB and 32 million pixels. Very large images are scaled for the on-page preview, while the downloaded PNG is rendered from the original image dimensions.
The tool includes protanopia, deuteranopia and tritanopia, plus an achromatopsia view. Protanopia and deuteranopia affect red-green discrimination, while tritanopia affects blue-yellow discrimination. Achromatopsia is shown as a no-color approximation.
No simulator can reproduce one person's exact perception. This tool uses an established mathematical model to support design review, not medical screening or diagnosis. Perception varies with the type and severity of color vision deficiency, the display and viewing conditions.
Not by itself. A design should also meet relevant contrast requirements and avoid using color as the only cue. Add text, icons, shapes or patterns where meaning could disappear, and include disabled, hover, focus and error states in your review.
After the page has loaded, the image processing itself does not need an upload or remote conversion service. Browser caching determines whether the whole page can reopen without a network connection.
